In this paper solid state and sonochemical reaction methods

In this paper, solid state and sonochemical reaction methods are used to produce the Mgdoped bulk and nano LSMMO (0.050 ≤ x ≤ 0.100) manganite perovskite, respectively. The structural as well as the magnetic properties of LSMMO manganite perovskites are revealed employing different characterisation techniques. An organized examination of bulk and nano LSMMO perovskites samples is done by in-situ ultrasonic measurement.
Experimental
Results and discussion
Conclusions The bulk and nanostructured LaSrMgMnOmanganite perovskites with different Mg content (x = 0.050, 0.075 and 0.100) are produced using solid-state reaction and sonochemical methods. The crystallinity and phase purity of perovskites are determined by XRD studies with the lattice parameters, Mn–O bond length and Mn–O–Mn bond angle. Particle size of bulk LSMMO (260–850 nm) and nanoLSMMO manganite perovskites (23 and 86 nm) are estimated by microscopic characterization studies and found it increases with increase in Mg content. In-situ ultrasonic velocities and attenuation measurement shows the FM–PM transitions (T) at temperatures 368, 364, and 357 K for bulk BLSMMO050, BLSMMO075, and BLSMMO100 and 356, 351, and 345 K for nano NLSMMO050, NLSMMO075, and NLSMMO100 manganite perovskites. The diffused phase transition in nano LSMMO manganite perovskites occurs at lower TCwith the corresponding bulk sample and is also confirmed from in-situ ultrasonic studies. The diminishing DE interactions are evidenced by the broad FM–PM transition in nano LSMMO perovskites. The spin–phonon and electron–phonon couplings consequence the anomalies in velocity and attenuation are due single ubiquitin conjugating enzyme magnetostriction and dynamic Jahn–Teller effect. The phase transition temperature and other studies authenticate the in-situ ultrasonic studies are more informative in distinguishing bulk and nanostructured perovskite manganites.
Introduction Uncontrolled discharge of industrial wastewater is a serious environmental problem encountered in many parts of the world today (Attahiru et al., 2012). This is because of increased human activities and increase of industrialization. These human activities are causing species to disappear at an alarming rate from the ecosystem and it has been estimated that between 1975 and 2015 species extinction occurred at a rate of 1–11% per decade (Ahalya and Ramachendra, 2002). The presence of industrial wastewater laden with pollutants in the water ecosystem has diverse effects such as affecting the quality of life, ending up in food chain and affecting various species of animals such as fish. The most common human activities that cause challenges to fresh water environment are agriculture, urbanization, and manufacturing industries (Jalali et al., 2002). Of all pollutants in water, heavy metals have received a major concern due to the fact that they are toxic and they cannot be decomposed by in situ biological means and hence persist for a long time (Jackson et al., 2001; Mehmet and Sukru, 2006). Remediation of heavy metals from wastewaters has been studied and a number of various conventional technologies have been developed to remove heavy metals in water effluents before discharge. These techniques include: chemical precipitation, ion exchange, electro-deposition, biosorption, liquid–liquid extraction, adsorption, membrane separation, reverse osmosis and coagulation (Kratochvil and Volesky, 1998). These methods are suitable at high concentrations, are expensive to maintain and also result in production of large quantities of secondary pollutants such as sludge (Igwe and Abia, 2006; Abdel-Aty et al., 2013; Onyancha et al., 2008; Zouboulis et al., 2004). The search of more effective methods for heavy metal removal has led to the study of biosorption as an alternative (Nilanjana et al., 2007; Wang and Chen, 2009). Biosorption is non active metal uptake by biological materials such as algae, fungi, bacterial and agriculture biomass due to the presence of functional groups such as amino, hydroxyl and carboxyl which bind the metal via mechanisms such as adsorption, ion exchange and complexation (Wang and Chen, 2009; Nilanjana et al., 2007). The advantages of biosorption over the conventional technologies include cost effectiveness, high efficiency and the fact that no sludge is formed during (Volesky, 2001).